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Biomedical subjects

Y F Heijdra

Publications and source records attributed to Y F Heijdra.

At least 19 recordsLinked to original sources
PubMed2006

Systemic immunological response to exercise in patients with chronic obstructive pulmonary disease: what does it mean?

Chronic obstructive pulmonary disease (COPD) is no longer seen as a pulmonary disease, but is increasingly associated with systemic effects with important clinical relevance. Systemic immunological changes in COPD patients are characterized by an increased number of circulating inflammatory cells, functional changes of the inflammatory cells, elevated plasma levels of cytokines, and oxidative stress. Physical exercise induces an abnormal systemic inflammatory and oxidative response in COPD patients, which is seen in both the circulation and the peripheral muscles. Although mechanisms and consequences of these effects are not yet fully understood, they could be harmful in COPD patients by inducing damage or functional changes in, for example, skeletal muscles. Whether these changes of the immune system can also affect the susceptibility to infections in these patients is unknown. The concept of COPD as a systemic rather than only a pulmonary disease also opens new perspectives on the development for new therapeutic interventions. The effects of new antioxidative and anti-inflammatory agents are investigated. A better understanding of the complexity of the systemic effects will aid the development of new therapies and management strategies for patients with COPD.

Anti-Inflammatory Agents↗
PubMed2005

[Therapeutic dilemmas in patients with a centrally-located pulmonary embolism confirmed by spiral CT-scan but with no cardiogenic shock].

3 patients, 2 women aged 64 and 44 and 1 man aged 67, had severe dyspnoea and a large centrally-located pulmonary embolism (PE) without any accompanying arterial hypotension. They were all given conventional anticoagulation therapy, although thrombolytic therapy was also considered. The women recovered but the man eventually died of a second massive embolism. PE is a disease with a potentially high mortality. Patients with cardiogenic shock due to PE are candidates for thrombolytic therapy. A subset of patients with right-ventricular dysfunction (submassive PE) also have a poorer prognosis despite the absence ofarterial hypotension or shock. Spiral CT-scan is becoming the first-line imaging test of preference in patients with suspected PE. Spiral CT enables the accurate visualization ofthrombi. The value of risk management using cardial biomarkers, spiral CT and echocardiography is not yet clear. There is no evidence that thrombolytic therapy is beneficial in patients with acute PE and right-ventricular dysfunction without overt shock.

Adult↗
PubMed2005

Skeletal muscle contractility is preserved in COPD patients with normal fat-free mass.

AIM: Peripheral muscle dysfunction often occurs in patients with chronic obstructive pulmonary disease (COPD). The muscle dysfunction may be caused by a loss of force-generating capacity, resulting from a loss of muscle mass, as well as by other alterations in contractile properties of skeletal muscle. METHODS: The maximal isometric voluntary strength and fatigability were determined in hand-grip and quadriceps muscles from nine male COPD patients (FEV(1) 30-50% predicted) and control subjects matched for fat-free mass (FFM), physical activity level and age. Contractile properties and fatigability of the quadriceps muscle were also studied with electrically evoked isometric contractions. RESULTS: The maximal voluntary force (MVC) and fatigability of the handgrip muscle did not differ between the COPD patients and control subjects. Also the MVC of the quadriceps muscle and the rate of force rise, contraction time, force-frequency relationship and fatigability, as determined with electrically evoked contractions, were similar in patients with COPD and control subjects. CONCLUSION: Skeletal muscle strength, contractile properties and fatigability are preserved in patients with moderate COPD and a normal FFM and activity level. This suggests that skeletal muscle dysfunction does not take place during moderate COPD until cachexia and/or a decline in physical activity occur.

Adipose Tissue↗
PubMed2005

Pulmonary hypertension: its diagnosis and management, a multidisciplinary approach.

Pulmonary hypertension is a devastating complication of various, but rare diseases and can also occur as an isolated entity. It causes morbidity and mortality in all patients. Ongoing research has provided some insight into the pathophysiology and clinical manifestations, and new therapeutic options have recently become available for some types of pulmonary hypertension. In order to provide optimal care for an individual patient it is mandatory to establish the type and severity of the pulmonary hypertension in each patient. The diagnostic protocol used in our hospital is presented along with a description of two case histories. An algorithm of the different therapeutic strategies now available is given as well as recommendations for follow-up.

Adult↗
PubMed2002

Pleural small cell carcinoma in pre-existent asbestos related pleural disease.

Extrapulmonary small cell carcinoma (SCC) is a very rare disease, and a primary pleural manifestation is extremely rare. A case of SCC of the pleura in a 66-year-old man with pre-existent asbestos-related pleural plaques is presented. This is the first case of pleural SCC in a patient with asbestos-induced pleural disease and the third reported case of a pleural SCC. The SCC developed in an area with pre-existent pleural thickening, underlining the need for careful analysis of alterations in the manifestation of pleural disease in patients with asbestos exposition.

Aged↗
PubMed2002

Combined treatment with acetazolamide and medroxyprogesterone in chronic obstructive pulmonary disease patients.

Medroxyprogesterone acetate (MPA) and acetazolamide (ACET) are two ventilatory stimulants which are used in hypoxic and hypercapnic patients with chronic obstructive pulmonary disease (COPD). In a double-blind randomised study, the effects of a 2-week treatment with MPA (30 mg b.i.d.) or ACET (250 mg b.i.d.), followed by a 2-week treatment with a combination of both drugs (MPA/ACET), on daytime and nocturnal ventilatory and blood gas parameters in 17 stable hypercapnic COPD patients were investigated. ACET, MPA and MPA/ACET treatment decreased mean daytime carbon dioxide tension in arterial blood by 0.4, 0.7 and 1.2 kPa, respectively. Minute ventilation was improved only with combined therapy, from 9.3 to 11.2 L x min(-1). With MPA/ACET therapy, the hypercapnic and hypoxic ventilatory responses significantly increased, from 3.7 to 5.8 L x min(-1) x kPa(-1) and from -0.13 to -0.40 L x min(-1) x %(-1), respectively. The mouth exclusion pressure response to hypoxia increased during combination therapy, from -0.01 to -0.03 kPa %(-1). Nocturnal end-tidal carbon dioxide tension decreased with MPA and MPA/ACET treatment, by 0.9 and 1.4 kPa, respectively. MPA/ACET significantly increased mean nocturnal arterial oxygen saturation values, from 85.5 to 90.2%. The authors conclude that short-term combined treatment with medroxyprogesterone acetate and acetazolamide has a more favourable effect on day and night-time blood gas values and chemical drive than single drug treatment.

Acetazolamide↗
PubMed2001

Effect of acute metabolic acid/base shifts on the human airway calibre.

Acute metabolic alkalosis (NaHCO(3)), acidosis (NH(4)Cl), and placebo (NaCl) were induced in 15 healthy volunteers (12 females, median age 34 (range 24-56) years) in a double blind, placebo controlled study to evaluate the presence of the effects on airway calibre. Acid-base shifts were determined by capillary blood gas sampling. Measurements were performed at the maximal acid-base shift, 90 min after intervention. Airway resistance (R(aw)) and specific airway conductance (sG(aw)), were evaluated, as primary variables, pre and post intervention. Secondary variables, including bronchial responsiveness to histamine, maximal respiratory mouth pressures and grip strength, were evaluated post intervention. In alkalosis, base excess (BE) increased from -0.3 (-3.0-1.9) to 3.0 (1.0-4.8) mmol/l and pH increased from 7.41 (7.37-7.43) to 7.44 (7.39-7.47) (both P<0.01), accompanied by an increase in Pa(CO(2)): 4.7 (4.0-5.7) to 5.0 (4.7-6.1) kPa (P<0.05). R(aw) increased from 0.156 (0.134-0.263) to 0.169 (0.132-0.271) kPa s/L (P<0.05), sG(aw) decreased, but this was not statistically significantly. In acidosis, BE decreased from -0.2 (-2.0-2.2) to -3.5 (-6.3-1.1) mmol/l and pH decreased from 7.41 (7.39-7.45) to 7.36 (7.31-7.40) (both P<0.01), accompanied by a non-significant decrease in Pa(CO(2)). Changes in R(aw) and sG(aw) were contrary to those in alkalosis, but did not reach statistical significance. Acute metabolic acid-base shifts mildly influence the airway calibre in healthy human subjects.

Acidosis↗
PubMed2001

Underestimation of nocturnal hypoxemia due to monitoring conditions in patients with COPD.

STUDY OBJECTIVES: COPD patients run a risk of developing nocturnal oxygen desaturation. When evaluating patients with nocturnal hypoxemia, an unfamiliar hospital environment and the monitoring equipment may cause sleep disturbances. It was hypothesized that increased sleep disruption will lead to fewer instances of desaturation during a night of monitoring. DESIGN: The following forms of monitoring were evaluated prospectively on 3 nights for each patient: oximetry at home; polysomnography (PSG) at home; and PSG in the hospital. SETTING: Department of Pulmonology, Rijnstate Hospital Arnhem, The Netherlands. PATIENTS: Fourteen stable COPD patients (7 men; median age, 71.5 years; age range, 59 to 81 years; FEV(1), 32.5% predicted; FEV(1) range, 19 to 70% predicted) participated in the study. All subjects had significant instances of nocturnal arterial oxygen desaturation. Those patients with a sleep-related breathing disorder or cardiac failure were excluded from the study. MEASUREMENTS AND RESULTS: The mean nocturnal arterial oxygen saturation (SaO(2)) level was higher during PSG monitoring at home (89.7%; range, 77 to 93%) than during oximetry monitoring (88.5%; range, 80 to 92%) [p < 0.025]. The fraction of time spent in hypoxemia (ie, SaO(2) < 90%) was lower during PSG monitoring at home (40.8%; range, 5 to 100%) than during oximetry monitoring (59.9%; range, 6 to 100%) [p < 0.01]. Desaturation time (DeltaSaO(2) > 4%) was lower during PSG monitoring at home (22.1%; range, 3 to 63%) during PSG monitoring at home than during oximetry monitoring (50.4%; range, 4 to 91%) [p < 0.01]. A correction for actual sleep during PSG monitoring reduced the differences between PSG monitoring at home and oximetry monitoring, although a difference in the desaturation time remained (PSG monitoring at home, 31.9% [range, 2 to 75%]; oximetry monitoring, 50.4% [range, 4 to 91%]) [p = 0.041]. A comparison of sleep architectures for nights when PSG was being monitored showed a higher arousal index in the hospital than at home (PSG monitoring in the hospital, 5.6 arousals per hour [range, 2 to 16 arousals per hour]; PSG monitoring at home, 2.5 arousals per hour [range, 1 to 6 arousals per hour]) [p < 0.025], but no differences in SaO(2) levels were found between PSG monitoring at home and PSG monitoring in the hospital. CONCLUSION: The artifacts due to sleep-monitoring equipment may cause an underestimation of the degree of nocturnal hypoxemia in COPD patients. The addition of an unfamiliar environment causes more sleep disruption, but this does not affect nocturnal SaO(2) levels further.

Aged↗
PubMed2000

[Bupropion: an effective new aid for smoking cessation].

Smoking is responsible for a substantial percentage of the total morbidity and mortality in western society. In the Netherlands 34% of the population smoke. A considerable part of the smokers tried to stop smoking, but did not succeed. Since December 1999 a new type of anti-smoke therapy is available; bupropion chloride (Zyban). With this treatment an improvement in success ratio in comparison with placebo is described of 11-15% after a year in a healthy population. Combined with nicotine patches this percentage was 20%. These percentages are higher than those of nicotine replacement therapy alone (3-13%). It is very important that effects of bupropion are tested in high-risk patients with asthma, chronic obstructive pulmonary disease (COPD) and cardiovascular diseases as these groups may benefit most from cessation of smoking. Especially in the COPD group cessation of smoking makes a more substantial contribution to improvement of the disease process than the medication now available. Therefore, it might be considered to prescribe bupropion under strict control in this group even now, before definitive research results are obtained.

Antidepressive Agents, Second-Generation↗
PubMed2000

Verapamil causes decreased diaphragm endurance but no decrease of nocturnal O(2) saturation in patients with chronic obstructive pulmonary disease.

OBJECTIVE: In animal studies, it has been shown that verapamil reduces strength and endurance of the diaphragm and inhibits the beneficial effects of theophylline. We examined whether the use of verapamil in patients with severe chronic obstructive pulmonary disease (COPD) who use theophylline leads to a deterioration of diaphragmatic function resulting in a decrease of nocturnal O(2) saturation. METHODS: A double-blind, placebo-controlled crossover study was designed in eight stabile severe COPD patients [forced expiratory volume in 1 s (FEV(1)) 0.9 +/- 0.1 l] taking theophylline. The doses of theophylline ranged from 600 mg daily to 1200 mg daily (7.0 mg/kg daily to 16.9 mg/kg daily). Nocturnal recordings, maximal respiratory muscle strength and endurance tests, lung function, blood pressure, electrocardiogram and arterial blood gas analysis were performed after 6 days of verapamil and after placebo. RESULTS: A significant decrease of the endurance time from 7.7 min to 6.4 min was found in the threshold loading test. However, the mean nocturnal saturation values did not change significantly: 89.8% and 89.6%, respectively. Results of pulmonary function tests, arterial blood gas analysis and routine blood samples also did not change. CONCLUSION: The decrease of the respiratory muscle endurance after the use of verapamil is in line with experiments in animal diaphragms. However, the nocturnal saturation did not change. This finding suggests that the effect found on diaphragm endurance is of no clinical significance and that verapamil can be given to COPD patients without risk of worsening nocturnal saturation. However, this must be confirmed by future larger scale studies.

Aged↗
PubMed2000

Smoking cessation: which aids are worthwhile?

Smoking is a major preventable health risk in western society. In the Netherlands, it is held responsible for 86 and 36% of annual mortality from lung cancer and cardiovascular disease, respectively. Nevertheless about 33% of Dutch people smoke. Only 2% of smokers quit successfully after being advised to stop once by a physician. Although the medical profession should play a leading role in campaigns to stop smoking, general practitioners advise only 10% of their smokers to quit. An overview was made of the various aids that can be used to support attempts to quit smoking. Three aids: supportive schedules, nicotine replacement and bupropion chloride had proven long-term effectiveness in up to 5-10, 3-13 and 11-15% of the subjects, respectively. In conclusion, supportive counselling combined with nicotine substitutes or bupropion chloride is the most worthwhile intervention to support quitting attempts. Wider application of this strategy is expected to have major implications on morbidity (50% myocardial infarct risk reduction) and mortality in the Netherlands.

Antidepressive Agents, Second-Generation↗
PubMed2000

Volumetric measurements of peripheral oedema in clinical conditions.

Water-displacement volumetry can be used for quantifying the volume of the leg. However, not much is known about its application in patients with peripheral oedema of cardiopulmonary origin. We measured the reproducibility of a water-displacement apparatus with a solid object and in ten non-oedematous clinical patients (group A). The day-to-day variability of the leg volume was assessed in the same group. The diurnal variability was assessed in ten patients with persisting peripheral oedema (group B). The effect of treatment on the severity of peripheral oedema was evaluated in another nine patients with peripheral oedema, who were in need of diuretic treatment (group C). Volumetric results were compared to the ankle circumference method and the body weight method. The coefficient of variation was 0.16% in the fixed object and 0.47% in group A. The day-to-day variability was 1.52% after 1 day and 1.76% after a mean interval of 4.8 days. In group B, leg volume and circumference increased during the day (5.9%, P<0.001, and 2.4%, P<0.01, respectively), while body weight remained unchanged. In group C, leg volume, circumference and body weight decreased significantly after treatment (13.1%, P<0.01, 7.1%, P<0.05, and 5.9%, P<0.05). The correlation between the changes in volume and body weight was poor (r=0.37, P=0.33). In conclusion, (1) water-displacement volumetry is highly reproducible, (2) a diurnal variability of peripheral oedema was found, and (3) volumetry is a suitable tool for monitoring peripheral oedema, while the body weight method appears to be less accurate.

Aged↗
PubMed1996

Nocturnal saturation improves by target-flow inspiratory muscle training in patients with COPD.

Nocturnal desaturations during rapid eye movement (REM) sleep, caused by nonobstructive hypoventilation, occur frequently in patients with chronic obstructive pulmonary disease (COPD). This is partly caused by decreased activity of the intercostal and accessory muscles due to a lower motor command. The diaphragm has to compensate for the diminished activity of these muscles during REM sleep. However, in patients with COPD strength and endurance of the diaphragm may be affected by its unfavorable position on the length-tension curve because of hyperinflation. The aim of this study was to establish the causal relationship between respiratory muscle function and nocturnal saturation in patients with COPD. We hypothesized that target-flow inspiratory muscle training (TF-IMT) would improve nocturnal saturation. In 20 patients with stable COPD (FEV1 35.5 +/- 14.1% of predicted) and a mean nocturnal saturation below 92% we measured maximal inspiratory pressure (PImax), transdiaphragmatic pressure (Pdi), maximal sustainable inspiratory pressure (SIPmax), endurance time, and nocturnal saturation in Weeks 0, 4, and 10. During these 10 wk 10 patients underwent TF-IMT at 60% of PImax and 10 control patients received sham TF-IMT at 10% of PImax. PImax, Pdi, SIPmax, and the endurance time as well as the nocturnal saturation improved significantly in the 60% training group (by 3.0 +/- 1.5 kPa, 3.4 +/- 1.9 kPa, 1.5 +/- 1.4 kPa, 189 +/- 149 s, and 1.9 +/- 2.2%, respectively), whereas no changes occurred in the sham training group. Also, significant correlations were observed between the changes in Pdi, SIPmax, and endurance time on the one hand and the change in nocturnal saturation on the other. We conclude that TF-IMT improves the nocturnal saturation in patients with severe COPD by increasing respiratory muscle strength and endurance.

Data Interpretation, Statistical↗
PubMed1995

Nocturnal saturation and respiratory muscle function in patients with chronic obstructive pulmonary disease.

BACKGROUND: Nocturnal desaturations, mainly caused by hypoventilation, occur frequently in patients with chronic obstructive pulmonary disease (COPD). Daytime arterial oxygen and carbon dioxide tensions (PaO2 and PaCO2) appear to predict which patients will desaturate at night. It is unknown if respiratory muscle strength, which may be decreased in these patients, plays an additional part. METHODS: Polysomnography, maximal respiratory pressures, lung function, and arterial blood gas tensions were measured in 34 patients with COPD (mean (SD) forced expiratory volume in one second (FEV1) 41.7 (19.9)% pred). RESULTS: Significant correlations were found between the mean nocturnal arterial oxygen saturation and maximal inspiratory mouth pressure (r = 0.65), maximal inspiratory transdiaphragmatic pressure (r = 0.53), FEV1 (r = 0.61), transfer coefficient (KCO) (r = 0.38), arterial oxygen saturation (SaO2) (r = 0.75), and PaCO2 (r = -0.44). Multiple regression analysis showed that 75% of the variance in nocturnal SaO2 (70%) and FEV1 (5%). CONCLUSION: Inspiratory muscle strength and nocturnal saturation data are correlated, but daytime SaO2 and FEV1 remain the most important predictors of nocturnal saturation.

Aged↗
PubMed1994

Topological analysis of the brainstem of the bowfin, Amia calva.

This paper presents a survey of the cell masses in the brainstem of the generalized actinopterygian fish Amia calva, based on transversely cut Nissl-, Klüver-Barrera-, and Bodian-stained serial sections. This study is intended to serve a double purpose. First it forms part of a now almost complete series of publications on the structure of the brainstem in representative species of all groups of vertebrates. Within the framework of this comparative program the cell masses in the brainstem and their positional relations are analyzed in the light of the Herrick-Johnston concept; according to this the brainstem nuclei are arranged in four longitudinal, functional zones or columns, the boundaries of which are marked by ventricular sulci. The procedure employed in this analysis essentially involves two steps: first, the cell masses and large individual cells are projected upon the ventricular surface, and next, the ventricular surface is flattened out, that is, subjected to a one-to-one continuous topological transformation (Nieuwenhuys [1974] J. Comp. Neurol. 156:255-267). The second purpose of the present paper is to provide a cytoarchitectonic basis for experimental analysis of the fiber connectivity in the brainstem of Amia. Five longitudinal sulci--the sulcus medianus inferior, the sulcus intermedius ventralis, the sulcus limitans, the sulcus intermedius dorsalis, and the sulcus lateralis mesencephali--could be distinguished. Some shorter grooves, present in the isthmal region, clearly deviate from the overall longitudinal pattern of the other sulci. Although in Amia most neuronal perikarya are contained within a diffuse periventricular gray, 40 cell masses could be delineated: Eight of these are primary efferent or motor nuclei, 10 are primary afferent or sensory centers, seven are considered to be components of the reticular formation, and the remaining 15 may be interpreted as "relay" nuclei. The topological analysis yielded the following results. In the rhombencephalon the gray matter is arranged in four longitudinal columns or areas, termed area ventralis, area intermedioventralis, area intermediodorsalis, and area dorsalis. The sulcus intermedius ventralis, the sulcus limitans, and the sulcus intermedius dorsalis mark the boundaries between these morphological entities. These longitudinal areas coincide largely, but not entirely, with the functional columns of Herrick and Johnston. The most obvious incongruity is that the area intermediodorsalis contains, in addition to the viscerosensory nucleus of the solitary tract, several general somatosensory and special somatosensory nuclei.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Effects of body position, hyperinflation, and blood gas tensions on maximal respiratory pressures in patients with chronic obstructive pulmonary disease.

BACKGROUND: Inspiratory muscle strength in patients with chronic obstructive pulmonary disease (COPD) can be affected by mechanical factors which influence the length of the diaphragm, and by non-mechanical factors. The aim of the present study was to evaluate firstly the effects of body position on respiratory pressures and, secondly, to determine the relative contribution of age, body mass index (BMI), lung volumes, and arterial blood gas tensions to respiratory muscle strength. METHODS: Thirty male patients with stable COPD (mean FEV1 40.4% predicted) participated in the study. Maximal inspiratory and expiratory mouth pressures (PImax, PEmax) and maximal inspiratory transdiaphragmatic pressures (PDI) in the sitting and supine position, lung function, and arterial blood gas tensions were measured. RESULTS: Mean (SD) PImax in the sitting position was higher than in the supine position (7.1(2.3)kPa v 6.4(2.2)kPa respectively). In contrast, PDI in the sitting position was lower than in the supine position (10.0(3.5)kPa v 10.8(3.7)kPa respectively). PEmax was higher in the sitting position (9.3(3.0)kPa) than in the supine position (8.7(2.8)kPa). Significant correlations were found between inspiratory muscle strength on the one hand, and lung function parameters, BMI, and arterial blood gas tensions on the other. CONCLUSIONS: Inspiratory muscle strength in patients with COPD is influenced by mechanical factors (body position, lung volumes) and non-mechanical factors (BMI, FEV1, and blood gases). PImax and PEmax are lower in the supine position while, in contrast to healthy subjects, PDI is higher in the supine position than in the sitting position.

Aged↗
PubMed1993

Differences between sniff mouth pressures and static maximal inspiratory mouth pressures.

Measurements of static maximal inspiratory mouth pressure (PImax) and dynamic sniff mouth pressure (Psniff) are frequently used to assess inspiratory muscle strength. The aim of the present study was to examine, in 42 healthy subjects, the equivalence of PImax and Psniff, the influence of body posture on PImax and Psniff, and the effects of nasal patency and repeated manoeuvres on Psniff. PImax was significantly higher than Psniff, 11.05 +/- 0.42 versus 8.53 +/- 0.31 kPa. Because of the low agreement between PImax and Psniff, the two measurement methods were not interchangeable. The limits of agreement were 2.56 +/- 3.92 kPa. Sitting PImax was 11.05 +/- 0.42 kPa, and supine PImax was 9.36 +/- 0.41 kPa. Sitting and supine Psniff were 8.53 +/- 0.31 kPa and 7.52 +/- 0.33 kPa, respectively. Psniff performed with one nostril open instead of two, was higher: 9.67 +/- 0.32 kPa left and 9.62 +/- 0.32 kPa right versus 8.53 +/- 0.31 kPa when both nostrils were open. After 20-28 sniff manoeuvres, Psniff fell from 8.43 +/- 0.31 kPa to 7.83 +/- 0.30 kPa, suggesting some mechanism of inspiratory muscle fatigue. We conclude that measurement of sitting PImax yields the highest values for inspiratory muscle strength. The two measurement methods, Psniff and PImax, are not interchangeable. Measurement of Psniff is affected by nasal patency.

Adult↗